what is the "Dissolve" tool for rasters?

[JamalNUMAN]

what is the "Dissolve" tool for rasters?

please, see the attached image that shows my question

I'm trying to dissolve the cell of the raster based on the Iprime field, but couldn't fine an equivalent tool.

I tried to use the "reclassify" tool but resulted raster was meaningless!

thank you

regards

Jamal

[NawajishNoman]

Hi Jamal,

If I understand your question correctly (the image is very small so I can't really see it clearly), you can use the Lookup tool to create a new raster using Iprime as the lookup field.

Please let me know if it does not work for you.

Thanks,
Noman
Esri, Redlands, CA.

[KylePurdon]

I think I found the loophole. The IPRIME Field in your raster is a "Double" value. The tools seem to only like Floating Point or Integer values. If you can live with your values *10 you can just make an integer field and use the field calculator. Then use the lookup tool (It works, I tried it). If you create a floating point field or keep the double and use the lookup there is an Arc10 glitch that makes 0.4 0.40000012 (or adds some random decimal to the end).

Where is this data coming from? Do you have an original file/files you used to create this raster? With that I could provide some more help.

So to review the loophole is:

• Create a new field of type integer


• Calculate value to be IPRIME * 10


• Use the lookup tool to create a new raster based on your new integer field


• There ya go.... a nice roundabout method

[JamalNUMAN]

I think I found the loophole. The IPRIME Field in your raster is a "Double" value. The tools seem to only like Floating Point or Integer values. If you can live with your values *10 you can just make an integer field and use the field calculator. Then use the lookup tool (It works, I tried it). If you create a floating point field or keep the double and use the lookup there is an Arc10 glitch that makes 0.4 0.40000012 (or adds some random decimal to the end).

Where is this data coming from? Do you have an original file/files you used to create this raster? With that I could provide some more help.

So to review the loophole is:

• Create a new field of type integer


• Calculate value to be IPRIME * 10


• Use the lookup tool to create a new raster based on your new integer field


• There ya go.... a nice roundabout method

Thank you Kyle for the help. finally it did work!

now i got a dissolved raster with the values of 0.2, 0.4, 0.6, 0.8 and 1
i have another raster of the values: a, b, c and d

what i need now in to combine them then to add a field in which I'm going to apply the If statement below:

----------------------------------------------------------------------------
if [CtachType] = "a" then
Select Case [Iprime]
Case .2
OP= 0
Case .4
OP= 0
Case .6
OP= 0
Case .8
OP= 0
Case 1
OP= 0
end select

else

if [CtachType] = "b" then
Select Case [Iprime]
Case .2
OP= .2
Case .4
OP= .4
Case .6
OP= .6
Case .8
OP= .8
Case 1
OP= 1
end select

else

if [CtachType] = "c" then
Select Case [Iprime]
Case .2
OP= .4
Case .4
OP= .6
Case .6
OP= .8
Case .8
OP= 1
Case 1
OP= 1
end select

else

if [CtachType] = "d" then
Select Case [Iprime]
Case .2
OP= .6
Case .4
OP= .8
Case .6
OP= 1
Case .8
OP= 1
Case 1
OP= 1
end select

end if
end if
end if
end if
-----------------------------------------------------------------------------------------
unfortunately, the combine tool switches the original values to another ones!!!!! so that i can't apply the above If statement!!!!

very confusing and exhausting!!!!!!!!

how can i combine these two rasters but to keep the original values to proceed in the analysis???

please, see the attached images. The second image shows the flow chart that i apply in order to derive what we call I-map.

in order to derive the I-map, 4 main rasters are involved:

Land use: forest, field/meadow/pasture
Slope: <3.5%, 3.5%-27%, >27%
Hydraulic conductivity: Type A, Type B, Type C, Type D, Type E, Type F
Surface catchment: a, b, c, d

then these rasters are combined according the logic illustrated in the flow chart (2nd image in the attachment)

in each single step of the analysis, i got stuck!!!! ArcGIS doesn't give a smooth path to accomplish the analysis straight forward!!!!


So how can i combine the two rasters but to keep the original values????

regards

Jamal

[KylePurdon]

A combination that in-depth is a bit out of my realm. It seems if would best be accomplished with some sort of script or combination of conditional statements. You may even take this to the geoprocessing or other sections of the forums.

Maybe someone with a bit more experience can help out!

Best of luck!

[SaseenNajjar]

I'm not 100% positive, but it seems that the Lookup (Spatial Analyst) in ArcGIS Pro 10 acts like a dissolve tool for rasters.